1981

4.1

1989

4.5

1993

6.2

1950

4.0

1994

6.3

1988

7.5

1987

4.0

1986

5.3

1985

5.2

1934

6.5

1941

2.8

1989

2.8

2004

4.8

1968

6.6

2007

6.1

1984

5.8

1984

6.8

2008

6.7

1955

4.7

1990

4.9